Natural variations in the pitch of spoken utterances convey important linguistic and emotional information to the listener. For children in particular, these prosodic cues are critical in the early stages of language learning. In tonal languages, the rapid changes in pitch carry lexical meaning. For young children, therefore, the ability to hear subtle differences in voice pitch is of great importance during the early years as they acquire their native language. Little, however, is known about children's sensitivity to subtle changes in voice pitch. Today, children who were born deaf or lost their hearing early in life routinely receive cochlear implants. Although cochlear implants facilitate the perception and acquisition of spoken language well, they are limited in the amount of voice pitch information that can be transmitted to the listener. It is, however, still possible that the early-implanted brain of young children, which is more adaptive than that of adults, may be able to overcome the limitations of the device to some extent. The goals of this project are to: i) measure the psychophysical sensitivity of school-aged normally hearing and cochlear-implanted children to changes in voice pitch;ii) quantify children's ability to process speech intonation and lexical tones using different acoustic cues when voice pitch is degraded;iii) quantify cochlear-implanted children's performance in similar tasks. The results of these studies will shed important new light on young children's sensitivity to voice pitch cues, how cochlear implantation might influence this sensitivity, and the extent to which the early-implanted auditory system can overcome an important limitation of the prosthesis. PUBLIC HEALTH RELEVANCE: The natural variations of voice pitch in everyday speech convey important linguistic information and are particularly important for language-learning by young infants and children. Little is known about young children's sensitivity to voice pitch, and children with profound hearing loss who have received a cochlear implant are at a particular disadvantage in regard to voice pitch information. The results of the present study will shed light on basic mechanisms of voice pitch processing by normally-hearing and cochlear-implanted children as they develop from age 6 to young adulthood.